Hardness testing apparatus



FIG. 1 is a frontal elevational view showing the new design of the present invention;

FIG. 2 is a top plan view showing the new design of the present invention;

FIG. 3 is a rear elevational view showing the new design of the present invention;

FIG. 4 is a bottom view showing the new design of the present invention;

FIG. 5 is a side view showing the new design of the present invention from the right side relative to the view of FIG. 1; and,

FIG. 6 is a side view showing the new design of the present invention from the left side relative to the view of FIG. 1. 

The ornamental design of a hardness testing apparatus, as shown and described. 